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author | hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-06-23 16:30:43 +0000 |
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committer | hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-06-23 16:30:43 +0000 |
commit | 6fb2f18178a7a2d8d7a166e8d418cddc7f0d5430 (patch) | |
tree | b69135bb367453ba3dfca8641a5f27c9cdc26160 /gcc/configure | |
parent | 88be2b3c486cb31e026fe212db72e7765d278597 (diff) | |
download | gcc-6fb2f18178a7a2d8d7a166e8d418cddc7f0d5430.tar.gz |
i386: Access external function via GOT slot for -fno-plt
i386 psABI has been updated to clarify that R_386_GOT32X and R_386_GOT32
relocations can be used to access GOT without base register when PIC is
disabled:
https://groups.google.com/forum/#!topic/ia32-abi/awsRSvJOJfs
32-bit x86 assembler and linker from binutils 2.26.1 and 2.27 support
call/jmp *_start@GOT
cmpl $0, bar@GOT
for both normal and IFUNC functions. We check if 32-bit x86 assembler
and linker have the fix for:
https://sourceware.org/bugzilla/show_bug.cgi?id=20244
before accessing external function via GOT slot for -fno-plt in both PIC
and non-PIC modes.
PR target/66232
PR target/67400
* configure.ac (as_ix86_tls_ldm_opt): Renamed to ...
(as_ix86_gas_32_opt): This.
(ld_ix86_tls_ldm_opt): Renamed to ...
(ld_ix86_gld_32_opt): This.
(R_386_TLS_LDM reloc): Updated.
(R_386_GOT32X reloc): New assembler/linker check.
(HAVE_AS_IX86_GOT32X): New. Defined to 1 if 32-bit assembler and
linker support "jmp *_start@GOT" and "cmpl $0, bar@GOT". Otherise,
defined to 0.
* config.in: Regenerated.
* configure: Likewise.
* config/i386/i386.c (ix86_force_load_from_GOT_p): Return
true if HAVE_AS_IX86_GOT32X is 1 in 32-bit mode.
(ix86_legitimate_address_p): Allow UNSPEC_GOT for -fno-plt
if ix86_force_load_from_GOT_p returns true.
(ix86_print_operand_address_as): Also support UNSPEC_GOT if
ix86_force_load_from_GOT_p returns true.
(ix86_expand_move): Generate UNSPEC_GOT in 32-bit mode to load
the external function address via the GOT slot.
(ix86_nopic_noplt_attribute_p): Check both TARGET_64BIT and
HAVE_AS_IX86_GOT32X before returning false.
(ix86_output_call_insn): Generate "%!jmp/call\t*%p0@GOT" in
32-bit mode if ix86_nopic_noplt_attribute_p returns true.
gcc/testsuite/
PR target/66232
PR target/67400
* gcc.target/i386/pr66232-14.c: New file.
* gcc.target/i386/pr66232-15.c: Likewise.
* gcc.target/i386/pr66232-16.c: Likewise.
* gcc.target/i386/pr66232-17.c: Likewise.
* gcc.target/i386/pr67400-1.c: Don't disable for ia32. Scan for
ia32 if R_386_GOT32X relocation is supported.
* gcc.target/i386/pr67400-2.c: Likewise.
* gcc.target/i386/pr67400-3.c: Likewise.
* gcc.target/i386/pr67400-4.c: Likewise.
* gcc.target/i386/pr67400-6.c: Likewise.
* gcc.target/i386/pr67400-7.c: Likewise.
* lib/target-supports.exp (check_effective_target_got32x_reloc):
New.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@237736 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/configure')
-rwxr-xr-x | gcc/configure | 62 |
1 files changed, 57 insertions, 5 deletions
diff --git a/gcc/configure b/gcc/configure index bfd2b8c64f5..800ab269e24 100755 --- a/gcc/configure +++ b/gcc/configure @@ -25899,13 +25899,13 @@ _ACEOF # Enforce 32-bit output with gas and gld. if test x$gas = xyes; then - as_ix86_tls_ldm_opt="--32" + as_ix86_gas_opt="--32" fi if echo "$ld_ver" | grep GNU > /dev/null; then if $gcc_cv_ld -V 2>/dev/null | grep elf_i386_sol2 > /dev/null; then - ld_ix86_tls_ldm_opt="-melf_i386_sol2" + ld_ix86_gld_opt="-melf_i386_sol2" else - ld_ix86_tls_ldm_opt="-melf_i386" + ld_ix86_gld_opt="-melf_i386" fi fi conftest_s=' @@ -25927,7 +25927,7 @@ else gcc_cv_as_ix86_tlsldm=no if test x$gcc_cv_as != x; then $as_echo "$conftest_s" > conftest.s - if { ac_try='$gcc_cv_as $gcc_cv_as_flags $as_ix86_tls_ldm_opt -o conftest.o conftest.s >&5' + if { ac_try='$gcc_cv_as $gcc_cv_as_flags $as_ix86_gas_opt -o conftest.o conftest.s >&5' { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 (eval $ac_try) 2>&5 ac_status=$? @@ -25935,7 +25935,7 @@ else test $ac_status = 0; }; } then if test x$gcc_cv_ld != x && test x$gcc_cv_objdump != x \ - && $gcc_cv_ld $ld_ix86_tls_ldm_opt -o conftest conftest.o $ld_tls_libs -lc > /dev/null 2>&1; then + && $gcc_cv_ld $ld_ix86_gld_opt -o conftest conftest.o $ld_tls_libs -lc > /dev/null 2>&1; then if $gcc_cv_objdump -d conftest 2>/dev/null | grep nop > /dev/null \ || dis conftest 2>/dev/null | grep nop > /dev/null; then gcc_cv_as_ix86_tlsldm=yes @@ -25958,6 +25958,58 @@ cat >>confdefs.h <<_ACEOF _ACEOF + conftest_s=' + .data +bar: + .byte 1 + .text + .global _start +_start: + cmpl $0, bar@GOT + jmp *_start@GOT' + { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for R_386_GOT32X reloc" >&5 +$as_echo_n "checking assembler for R_386_GOT32X reloc... " >&6; } +if test "${gcc_cv_as_ix86_got32x+set}" = set; then : + $as_echo_n "(cached) " >&6 +else + gcc_cv_as_ix86_got32x=no + if test x$gcc_cv_as != x; then + $as_echo "$conftest_s" > conftest.s + if { ac_try='$gcc_cv_as $gcc_cv_as_flags $as_ix86_gas_opt -o conftest.o conftest.s >&5' + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; } + then + if test x$gcc_cv_ld != x && test x$gcc_cv_objdump != x \ + && test x$gcc_cv_readelf != x \ + && $gcc_cv_readelf --relocs --wide conftest.o 2>&1 \ + | grep R_386_GOT32X > /dev/null 2>&1 \ + && $gcc_cv_ld $ld_ix86_gld_opt -o conftest conftest.o > /dev/null 2>&1; then + if $gcc_cv_objdump -dw conftest 2>&1 \ + | grep 0xffffff > /dev/null 2>&1; then + gcc_cv_as_ix86_got32x=no + else + gcc_cv_as_ix86_got32x=yes + fi + fi + rm -f conftest + else + echo "configure: failed program was" >&5 + cat conftest.s >&5 + fi + rm -f conftest.o conftest.s + fi +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_ix86_got32x" >&5 +$as_echo "$gcc_cv_as_ix86_got32x" >&6; } + + +cat >>confdefs.h <<_ACEOF +#define HAVE_AS_IX86_GOT32X `if test x"$gcc_cv_as_ix86_got32x" = xyes; then echo 1; else echo 0; fi` +_ACEOF + ;; ia64*-*-*) |